package com.fruit.utils;

import java.security.SecureRandom;  

import javax.crypto.Cipher;  
import javax.crypto.SecretKey;  
import javax.crypto.SecretKeyFactory;  
import javax.crypto.spec.DESKeySpec;  

/**
* DES加解密,支持与delphi交互(字符串编码需统一为UTF-8)
*  
* @author wym
*/

public class DESPlusUtil {  

    /**
     * 密钥
     */
    public static final String KEY = "xiongshao";  

    private final static String DES = "DES";  

    /**
     * 加密
     *  
     * @param src
     *            明文(字节)
     * @param key
     *            密钥，长度必须是8的倍数
     * @return 密文(字节)
     * @throws Exception
     */
    public static byte[] encrypt(byte[] src, byte[] key) throws Exception {  
        // DES算法要求有一个可信任的随机数源  
        SecureRandom sr = new SecureRandom();  
        // 从原始密匙数据创建DESKeySpec对象  
        DESKeySpec dks = new DESKeySpec(key);  
        // 创建一个密匙工厂，然后用它把DESKeySpec转换成  
        // 一个SecretKey对象  
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);  
        SecretKey securekey = keyFactory.generateSecret(dks);  
        // Cipher对象实际完成加密操作  
        Cipher cipher = Cipher.getInstance(DES);  
        // 用密匙初始化Cipher对象  
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);  
        // 现在，获取数据并加密  
        // 正式执行加密操作  
        return cipher.doFinal(src);  
    }  

    /**
     * 解密
     *  
     * @param src
     *            密文(字节)
     * @param key
     *            密钥，长度必须是8的倍数
     * @return 明文(字节)
     * @throws Exception
     */
    public static byte[] decrypt(byte[] src, byte[] key) throws Exception {  
        // DES算法要求有一个可信任的随机数源  
        SecureRandom sr = new SecureRandom();  
        // 从原始密匙数据创建一个DESKeySpec对象  
        DESKeySpec dks = new DESKeySpec(key);  
        // 创建一个密匙工厂，然后用它把DESKeySpec对象转换成  
        // 一个SecretKey对象  
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);  
        SecretKey securekey = keyFactory.generateSecret(dks);  
        // Cipher对象实际完成解密操作  
        Cipher cipher = Cipher.getInstance(DES);  
        // 用密匙初始化Cipher对象  
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);  
        // 现在，获取数据并解密  
        // 正式执行解密操作  
        return cipher.doFinal(src);  
    }  

    /**
     * 加密
     *  
     * @param src
     *            明文(字节)
     * @return 密文(字节)
     * @throws Exception
     */
    public static byte[] encrypt(byte[] src) throws Exception {  
        return encrypt(src, KEY.getBytes());  
    }  

    /**
     * 解密
     *  
     * @param src
     *            密文(字节)
     * @return 明文(字节)
     * @throws Exception
     */
    public static byte[] decrypt(byte[] src) throws Exception {  
        return decrypt(src, KEY.getBytes());  
    }  

    /**
     * 加密
     *  
     * @param src
     *            明文(字符串)
     * @return 密文(16进制字符串)
     * @throws Exception
     */
    public final static String encrypt(String src) {  
        try {  
            return byte2hex(encrypt(src.getBytes(), KEY.getBytes()));  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return null;  
    }  

    /**
     * 解密
     *  
     * @param src
     *            密文(字符串)
     * @return 明文(字符串)
     * @throws Exception
     */
    public final static String decrypt(String src) {  
        try {  
        	if (null != src) {
            return new String(decrypt(hex2byte(src.getBytes()), KEY.getBytes()));  
        	} else {
        		return src;
        	}
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return null;  
    }  

    /**
     * 加密
     *  
     * @param src
     *            明文(字节)
     * @return 密文(16进制字符串)
     * @throws Exception
     */
    public static String encryptToString(byte[] src) throws Exception {  
        return encrypt(new String(src));  
    }  

    /**
     * 解密
     *  
     * @param src
     *            密文(字节)
     * @return 明文(字符串)
     * @throws Exception
     */
    public static String decryptToString(byte[] src) throws Exception {  
        return decrypt(new String(src));  
    }  

    public static String byte2hex(byte[] b) {  
        String hs = "";  
        String stmp = "";  
        for (int n = 0; n < b.length; n++) {  
            stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));  
            if (stmp.length() == 1)  
                hs = hs + "0" + stmp;  
            else
                hs = hs + stmp;  
        }  
        return hs.toUpperCase();  
    }  

    public static byte[] hex2byte(byte[] b) {  
        if ((b.length % 2) != 0)  
            throw new IllegalArgumentException("长度不是偶数");  
        byte[] b2 = new byte[b.length / 2];  
        for (int n = 0; n < b.length; n += 2) {  
            String item = new String(b, n, 2);  
            b2[n / 2] = (byte) Integer.parseInt(item, 16);  
        }  
        return b2;  
    }  

    public static void main(String[] args) {  
        try {  
            String src = "21009000083";  
            String crypto = DESPlusUtil.encrypt(src);  
            System.out.println("密文[" + src + "]:" + crypto);  
            System.out.println("解密后:"
                    + DESPlusUtil.decrypt(crypto));  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  

}
